A SILENT BLINDING OCULAR DISEASE  WE  SHOULD KNOW
Glaucoma is a condition of  progressive optic neuropathy in which the fluid pressure inside the eye is sufficiently elevated to result in damage to the optic nerve head and thereby producing peripheral visual field loss. This condition commonly affects people between 30 to 60yrs of age although even newborn (congenital glaucoma) and the young (Juvenile Glaucoma) are also affected by this condition.The causes of Glaucoma can be broadly classified into primary (cause not exactly known) and secondary type (due to a known pre-existent ocular pathology).There are  more than 40 subtypes of glaucoma and the basic mechanisms are either due to increased production of the intraocular fluid -  aqueous  or its  decreased excretion out of the eye.It is to be noted that nearly 1% of our Indian population (1 million people) are affected with this disease. Glaucoma is the second largest (accounts for about 12%) cause  of preventable blindness in our country next to cataract.
 

Normal Picture with Normal field of vision	Glaucomatous damage to the optic nerve head results in constriction of the peripheral of the vision

Who are at Risk ?
Exact cause for Primary Glaucomas are unknown. Predisposing factors include:

•  Patients with family history of glaucoma (maternal/paternal background).
•  Patients with high intra ocular pressures (Ocular hypertensives)
•  Patients belonging to the  dark race population (Asians and Africans).
•  Increasing age and patients with high myopia.
•  Patients with systemic illnesses - diabetes, hypertension, asthma, heart failure,
•  History of long term steroid drug intake for asthma and arthritis.
•  Patients who are obese and chronic alcoholics are prone to have high intraocular pressures leading to glaucoma.Patients on long term specific Psychiatric medications - anti depressants and sedatives.

• Associated congenital abnormalities, high hypermetropic refractive error.
• History of repeated attacks of pain and redness in the eyes (Uveitis)
• Blunt injury to the eye can cause angle recession glaucoma.
• Long standing mature cataract causes lens induced glaucomas
• Post-operative complications after intraocular surgeries

What to do next with raised Intraocular pressure
Once ocular hypertension is detected, a detailed ophthalmic examination is done to rule out glaucomatous damage to the optic nerve head. Stereobiomicroscopic evaluation of the optic nerve and fundus is done. Careful Gonioscopic examination of the drainage angle is done to differentiate open angle from a narrow angle glaucoma. Peripheral visual field testing using the Humphrey Automated perimeter detects earliest field loss. Optic disc photography is done every year to compare the progression of the disease.  It should be realized and explained to the patient that the glaucomatous damages that have already occurred at the time of detection cannot be reversed and further evaluation and treatment are instituted only to preserve the existing vision and safeguard against further progression of  the disease.
 

Recording Intraocular pressure	Fundus examination of the optic nerve head for glaucomatous changes
HFA Machine for recording peripheral visual field	Visual field report
These test are done every one year to follow up progressive of the disease

Treatment Protocol Once diagnosed, treatment with antiglaucoma tablets and eye drops are started to bring down the target intraocular  pressures by 30-40% of the original value. Alternatively, surgical procedures or Laser treatment are advised if necessary to permanently bring down the intraocular pressures within safe tolerable limits.